Unique Disruption of Brain Circuits in Gulf War Syndrome

When she returned from serving in the Gulf conflict in 1991, US Air Force nurse Denise Nichols experienced sudden aches, fatigue and cognitive problems, but had no idea ‘what was causing them. They grew worse: even helping her daughter with multiplication tables became difficult, she says, and eventually she had to quit her job.

Nichols wasn’t alone. About a third of Gulf war veterans – possibly as many as 250,000 – returned with a similar set of symptoms.

Now an imaging study has found that these veterans have what appear to be unique structural changes in the wiring of their brains. This fits with the scientific consensus that Gulf War syndrome (GWS) is a physical condition rather than a psychosomatic one, and should be treated with painkilling drugs instead of counselling.

The military in various countries has in the past consistently denied that there is a physical basis to GWS. Although the US Department of Veterans Affairs (VA) now officially accepts that the disorder is physical, the issue has been mired in controversy.

Coughlin told the panel: “If the studies produce results that do not support the [VA’s] unwritten policy, they do not release them… On the rare occasions when embarrassing study results are released, data are manipulated to make them unintelligible… Anything that supports the position that Gulf War illness is a neurological condition is unlikely to ever be published.”

In response, the VA said that the organisation has a “long history of conducting world-class research studies that meet accepted and rigorous scientific standards”. They also note that “all allegations of malfeasance are taken seriously and are investigated fully”.

Cause still sought

Whatever the cause of GWS, it is certainly not psychological, says Bernard Rosof of Huntington Hospital in New York, although no single cause is known. Suggested causes include exposure to low levels of sarin gas in fallout when chemical munitions were destroyed, and a drug called pyridostigmine bromide, which soldiers were given to protect them from sarin.

It’s vital to find an objective test that will allow physicians to make a diagnosis, says James Baraniuk of Georgetown University in Washington, DC.

To that end, Baraniuk and colleague Rakib Rayhan examined 31 veterans with GWS, including Nichols. They scanned their brains using a technique called diffusion tensor imaging, which highlights the bundles of nerves, or white matter, connecting brain regions. They compared these to scans of 20 veterans who were not deployed in the Gulf.

The images indicate that in GWS, these nerve bundles break down and may have trouble forming connections: a phenomenon that has not been associated with any other illness. This suggests that the brain circuitry, rather than any specific brain area, is disrupted in people with the condition. Veterans with the worst symptoms tended to have the most pronounced abnormalities in their white matter.

Easily distracted

The damaged areas tended to be in fibres that connect pain-registering nerves to higher brain centres responsible for interpreting pain. Another affected area was the ventral attention network, which allows people to break their concentration to respond to a stimulus. This fits with the affected veterans’ tendency to be easily distracted and to have trouble with memory formation.

Because the number of people studied was small, it is not yet possible to draw a clear distinction between an affected brain and a normal brain, Baraniuk says. He next wants to look at similar scans of people with chronic fatigue syndrome or fibromyalgia – characterised by widespread chronic pain – both of which share some symptoms with GWS.

“It’s a very important paper,” says Robert Haley of the University of Texas Southwestern in Dallas, not least because it helps establish GWS as a treatable, physiological problem. But he says the team will have to examine dissected brain tissue from deceased veterans to better understand what the scans show.

The findings still do not pinpoint a specific cause or mechanism for the disorder. However, this type of scan might in the future help physicians distinguish people with the syndrome from others with similar symptoms. This could ensure that they receive long-term pain management rather than psychotherapy.

That’s good news for people like Denise Nichols, who believes that the VA has avoided addressing the problems people like herself have experienced. “We need help. Our bright hope is these researchers.”

“We will continue to learn and examine ways to improve treatment, process claims, and better care for these Veterans,” add the VA.